K. Vuorenvirta et al., Effect of black liquor carryover on selectivity of oxygen delignification - Brownstock washing plays a major role, PULP PAPER, 102(3), 2001, pp. 50-52
Carryover can be a problem at pulp mills if brownstock washing is inadequat
e. Because of the residual alkali present in black liquor and the exotherma
l oxidation reaction, the temperature in the oxygen delignification tower c
an increase and thus accelerate unselective reactions in the fibre. A labor
atory study was conducted on Finnish softwood brownstock to determine the l
evel of carryover-containing black liquor that adversely affects softwood p
ulp under oxygen delignification conditions and lowers the efficiency of ox
ygen delignification.